Facsimile printing telegraph system and apparatus



Oct. 4,1938. E. E. KLEINSCHMIDT ET AL FACSIMILE PRINTING TELEGRAPH SYSTEM AND APPARATUS Original Filed Aug. 4, 1930 3 Sheets-Sheet 1 fan pl? f INVENTORS 50mm F Alfl/WCHMIDT ATTO Oct. 4, 1938. E. E. KLEINSCHMIDT ET AL 2,131,741

FACSIMILE PRINTING TELEGRAPH SYSTEM AND APPARATUS Original Filed Aug. 4, 1930 s Sheeis-Sheet 2 1938. E. E. KLEINSCHMIDT ET AL 2,131,741

FACSIMILE PRINTING TELEGRAPH SYSTEM AND APPARATUS I Original FiledAug. 4, 1930 3 Sheets-Sheet 5 x; .u. \vLMMmmwww r mvm Ann Q %\h AAA mmm mmm INVENTO ATTO Patented Oct; 4, 1938 uurrrzo STATES PArsur orrms FACSIMILE PRENTING TELEGRAPH SYSTEM AND APPARATUS Edward E. Kleinschrnidt and Edward F. Kleinschmidt, Highland Park, Ill., assignors to Teletype Corporation, Chicago, Ill., a corporation of Delaware 21 Claims.

This invention pertains to printing telegraph systems and more particularly to facsimile telegraph systems and apparatus in which signal 3 codes representing scanning analyses of letters and other characters are transmitted character by character to form adirectly legible printed line character and in which successive characters occupy approximately equal lineal units of space in the line. I

" This application is a division of application Serial No. 475,264 filed, August 4, 1930 which issued on July 7, 1936 as Patent No. 2,046,328.

An object of the present invention is to provide a simple, efficient, and reliable facsimile printing telegraph apparatus wherein special control or synchronizing impulses over the line transmission conductor are not required nor any equivalent thereof, thereby materially simplifying the ap- .paratus. 1

A further object is to provide a facsimile printer so constructed that a legible record is attained even though the speed of the printer may vary appreciably from the speed of the transmitting unit to which it is responsive.

-The above and other objects are attained by providing a facsimile receiving mechanism which in response tofacsimileing signals received over the transmitting path will produce records which are essentially duplicates, one of which records *may be at times illegible but at least one of which records will be at all times legible. In the operation of the mechanism herein disclosed should the speed of thereceiving printer be exactly ac- ,curate ther'eceiVed intelligence will be recorded in a line parallel to the edge of the tape or other recording surface and any variation in speed will result in a slight sloping of the line of the record at an angle upward or downward so that the line but in such an occurrence a duplicate record will be produced which lies fully upon the surface of the receiving and recording tape.

A better understanding of the invention may be had from the following description, taken in conjunction with the accompanying drawings wherein,

Fig. 1 shows a schematic arrangement of the essential mechanical parts of a tape controlled .transmitter embodied in this invention;

Fig. 2 is a broken elevation taken on line 2-2 of Fig. 1; V

Fig. 3 is a section of permutation bars, selection bail, brush carriers, and code discs of the mechanism'of Fig.1 taken on line 33 of Fig. 1;

of the record will pass off theedge of the tape,

Fig. 4' shows a mechanical detail of gearing interconnecting apparatus in Fig. 1;

Fig. 5 is a plan of a tape adapted to control the apparatus of Fig. 1;

Fig. 6 is a perspective of receiving apparatus;

Fig. 7 is a section of printing apparatus of Fig. 6 takensubstantially centrally thereof;

Fig. 8 is a diagram of the printing elements of the receiver showing a record tape printing armature member, and a development of the printing edges of the spirally fluted printing wheel for producing duplicate images upon the receiving tape;

Fig. 9 shows a specimen of receiving tape produced at equal speeds;

Fig. 10 shows a specimen of receiving tape with the receiver running faster than its controlling transmitter as calculated in equivalent cycles transmitted and received;

Fig. 11 shows a similar tape as produced when the receiver'is running at a comparatively slower speed;

Fig. 12 is a side view of a code disc which forms a part of the transmitter of Fig. 1, shown also in Fig. 3 and elsewhere;

Fig. 13 is a diagram showing the analysis of a 7 character according to a method for prescanning,

the character shown being that character transmitted by the specific code disc shown in Fig. 12;

Fig. 14 shows a receiving device having speed 55 on shaft 56 and thus drives transverse shaft 56.

of the transmitter of Fig. 1 at the same angular speed as cam shaft 53.

Referring to Fig. 1,.a code transmitter 6|] is driven by a power cam shaft 53 which carries three cams. A first cam 6| controls the action of feeler bars 62 of which there are six in the device as shown, the feeler bars 62 being suincient in number to detect all of the code holes in control tape 63. Apparatus herein illustrated is adapted to use a six-hole cross-perforated tape, although the device may be arranged to be controlled from any desiredi'orm of tape. Cam GI engages roller 66 on cam follower 61 pivoted at 68 to the transmitter frame. Cam follower 0'! is under tension of spring I9 and has arm 69 with transverse flange lI which engages six lugs I2 on the six feeler bars 62. Each feeler bar 62 is provided with an individual spring I3 urging it upward, with a tape testing pin I0 and with a stop lug I5. Springs I3 extend to the center frame slide guides TI and I8 fixed in the frame. Tape at 10 and the six feeler bars operate freely in guide is perforated at 8| opposite each tape testing pin I4.

Arm 69 carries pawl attached pivotally at 85 and under tension of spring 81 withdraws the pawl against the teeth of ratchet 90. The ratchet and tape feed sprocket wheel 9I are fixed to shaft 92 which is journaled in the frame. Pins on feed wheel 9| engage said holes in tape 63 in well-known manner to feed the tape in operation.

Follower 6'! has a stop tooth 96 engageable by tooth 97 in a manually controlled lever 98 pivoted at 99 to the frame of the transmitter. With shaft 53 and cam 6| in operation and with lever 98 in the full line position shown, follower 67 is held from movement as cam 9| rotates and operation of the transmitter is prevented. With lever 98 moved to the dotted line position shown, follower 61 is freed for movement under influence of spring 70 and cam SI, and transmitting operations may proceed under control of tape 53.

A second cam IOI carried by shaft 53 controls the action of transfer levers I92 which are equal in number to the tape feeler bars 62 and are controlled thereby. Cam IOI engages roller I06 on cam follower I07 pivotally mounted at I08 to the frame. Cam follower I01 has an arm I99 with transverse flange I I0 which engages six lugs I I2 on the six transfer levers I92. Each lever I 02 is provided with individual spring H3, with a testing finger H4 and with a power lug II5. Springs II3 are secured to the transmitter frame at II 6 and the six transfer levers are pivotally mounted for independent movement upon a common pivot shaft Ill fixed in the frame. Cam follower I0'I is under tension of spring II9 secured to the frame at I20.

A third cam I 2| carried by shaft 53 engages roller I26 on cam follower arm I2! formed integrally with ball I22. Bail I22 is under tension of two springs, spring I29 attached to the frame at I30 and spring I3I attached to the frame at I32. Bail I22 operates freely in longitudinal and vertical directions in slide guides I34, I35, and L35 fixed to the transmitter frame. Guides I34 and I35 are provided with inclined cam surfaces I34A and I35A which are engaged by inclined edges IS IB and I353 respectively of bail I22. As cam I2I rotates, the cooperation of cam I2I, surfaces I34A, I 34B, edges I35A, I353, and springs I29, I3I shifts bail I22 into and out of its dotted line position, the shift being made momentarily and once for each rotation of shaft 53.

Six permutation bars I59 provided with selecting notches I5I slide in slotted guides I52 and I53 fixed to the transmitter frame. Each bar I59 is provided with an individual spring I55 secured to the frame at I56. Each bar I50 is individual to andcontrolled by each of the six transfer levers I02, and springs I55 draw the six bars I50 severally against the lugs H5 which determine the normal position of rest of the bars, the normal position of levers I02 and lugs II5 being determined by springs H3 and by the flange I I0 of follower I91, whose position is determined by engagement of roller I06 and cam I 0I.

Each bar I50 has a locking notch I51 adapted to be engaged by point I59 of a latch I60 of which there are six individual to six bars I50. Secured to each latch I65 is a spring I6I attached also to the transmitter frame at I62. The six latches I90 are pivotally mounted upon a common pivot IE3 fixed in the frame and are crossed by a striker pin I66 carried by a restoring bell crank I 67 pivotally mounted at I68 upon the frame and under tension of spring I69 attached to the frame at I10. Bell crank I61 rotates on its pivot. I68, and extension I'II thereof at all times slidably engages end I72 of selector bail I22. Notches I5I of bars I50 are preferably arranged in a manner similar to the permutation code bars commonly used in tape printing telegraphs and are preferably arranged to operate under control of permutation code perforations in tape 63.

Referring to Fig. 3 in connection with Fig. 1, a series of bell cranks I90, one for each character to be transmitted, are pivotally mounted upon a common pivot shaft I9I. Each bell crank I90 has an individual spring I 92 secured to the frame at I93 which springs urge arms I94 of bell cranks I 90 into engagement with the six permutation bars 455, thus conditioning the bell cranks to be selectively controlled by sets of aligned notches 55E of bars I50 in accordance with control perforations in tape 63.

Each bell crank I90 carries an insulated brush 200. The brushes 200 contact severally with code discs 29%, one for each character or signal to be transmitted, all rigidly secured to shaft 56 and spaced apart by collars 205. Each code disc 20I has associated with it an individual brush 200 with its operating member I90.

All the brushes 290 are connected to a common wire 299 and all code discs 20I are connected electrically through shaft 56 and through the transmitter frame to a common wire 2). Each code disc has a high radius or contact surface 2H at each point where a signal is to be transmitted. Contact surfaces 2II are arranged on each code disc in such manner as to transmit the desired signals.

Code discs 20I are designed according to a novel method of prescanning in which characters or symbols to be transmitted are divided into any desirable number of transmitting units of areas and in which the several unit areas thus created are assigned in order of scanning to the periphery of the disc 20L either the dark areas or the light areas of the character being represented by the high surfaces 2II to engage the brush 200 to send a signal, depending upon the method of transmission adopted.

By way of example a prescanning of the letter R together with the area of space between the letter and the preceding letter is shown in Figs. 12 and 13. The total area of the letter and space there shown is divided into 450 unit areas arranged in eighteen vertical strips of twenty-five units each. As shown in Fig. 13, the eighteen strips are laid off in eighteen angular sectors on the code disc, and each angular sector is divided into twenty-five angular units each corresponding to a unit area of the corresponding vertical strip. The code disc periphery is then executed by recessing the corresponding disc unit sections of each sector where the respective scanning unit areas are light, thus producing raised surfaces such as 2II where the scanning units are dark. A blank interval is left below and/or above each letter or character, shown in Fig. 13 as three lower horizontal blank rows. Prescan- #3 of the seventh sector of disc 2!]I.

ning or generation of the code begins at unit area 23I in Fig. 13 and progresses vertically to" area 232. Sinceall of the unit areas in this strip are white, the twenty-five units of the first sector 2 between radii 23IA and 232A of Fig. 12 are recessed, forming a portion of. a continuous lowradius arc 230. Prescanning then proceeds for the next sector beginning with unit area 233 and ending with unit area 234 of the second vertical istrip and between radii 232A and 234A on the code disc periphery of Fig. 12. All areas of the second strip being white, the second sector of the code disc is also completely recessed. Presoanning then proceeds for the third sector beginning with area 235 and ending with area 236 of Fig. 13, resulting in the third recessed sector between radii 234A and 236A. Prescanningproceeds from unit area 231 to unit area 238 then 239 and 240, and 2M and 242, completing three groups of twenty-two black unit areas each preceded by three white unit areas resulting in corresponding raised portions 231A, 239A, and MIA,

in Fig. 12. Prescanning proceeds in like manner "for the seventh sector, giving thirteen white unit areas for recessed arc section 254 of disc ZIlI, then three black unit areas for first arc 2II, six white unit areas corresponding to recessed are 255, and three black unit areas for final are In this manner prescanning proceeds through the remaining eleven strips of Fig. 13 to complete the periphery of code disc Zlll of Fig. 12, shown also in Fig. 3.

In like manner each other code discis developed to transmit the other desired characters. Every letter or character to be transmitted is preceded by the desired space between it and the preceding letter so that every code disc comprises a letter space and character code, and the first three sectors of each disc are allotted to transmission of the letter space, thereby providing a'depressed spacing are 236 extending from radius 23IA to 236A of Fig. 10 on each disc.

starting arcs 230 are in alignment.

Controlling tape 63, Fig. 5, may be perforated in any well-known manner with successive rows of perforations 251 arranged in controlling combinationsin accordance with a six-unit permutation code and with one or more rows of feed holes to be engaged by the pin on the tape feed Wheel 9I of the transmitter.

For purposes of remote control, a magnetically controlled reperforator 258 controlled'by signal selector magnet 259 is utilized. Selectormagnet Y 259 is connected in line 260 which is in turn controlled by a six-unit permutation code tape transof the tape 253 adjacent to the transmitting mechanism 60, it will be obvious that the keyboard perforator264 and tape 263 may be utilized directly to control the transmitter 60 in place of the reproduced tape 63 if desired.

Operationof transmitter T start transmission, the shafts 53 and 56 being in rotation and perforated tape 63 being in position in guide Bil, manual lever 98 is lifted .when'apex of cam BI is under roller 66, thus re- Thecode discs are .thenfixed on shaft 56 in such manner that the leasing'cam follower 61. Notch 91 of lever 98 and detent 96 of cam follower 61 are so shaped that under theactionof spring III the raising of lever 98 is prevented until roller 66 is on the peak of cam 6|, thereby insuring initiation of transmission at the beginning of a cycle. With cam 6| in the position shown in Fig. 1', discs 20I will be in the position shown in Fig. '3 and cam roller 68 will be lowered during approximately 120 of angle of rotation of shaft 53. Rotation of cam SI allows spring '16 to rotate cam follower 61 counterclockwise about its pivot 68 to lift flange II out of engagement with the six lugs I2 on tape feeler bars 62 which rise under influence of spring I3. When feeler bars 62 rise, should any feeler pins register with any holes in tape 63, said pins will pass through said'holes and each feeler bar 62 will rise to remove its stop lug I5 from thepath of finger M4 on corresponding transfer lever I62. Accordingly feeler bars 52 will be'positioned in a code combination in accordance with the controlling permutation code perforations.

Rotation of shaft 53 for approximately 110 from the zero position shown in Fig. 1 carries cam I2I into engagement with roller I26 to shift follower I21 and selector bail I22, thus moving said bail to dotted position. Verticalmovement of the selector bail I22 causes it to engage arms I94 of all bell cranks I90 to raise the members clear of permutation bars I56 to permit setting of the bars immediately after the last transmitting arcs of all discs 20I have passed their respective brushes 200.

Movement to the left of bail I22 causes rotation of bell crank I61 about its pivot I58 which causes striker pin I66 carried thereby toengage and to depress all latches I56. This releases all operated permutation bars I55 and allows them to return to their right-hand position under action of their individual springs I55. Further rotation of shaft 53 to about 120 from zero angle next causes the low portion of transfer cam IBI to pass under roller I96, thus allowing spring IIQ to rotate cam follower IIlI counterclockwise lifting flange III out of engagement with lugs H2 to release the six transfer levers 902. At this point in the cycle of operations feeler bars 62 have assumed their selective positions in accordance with the code for the character to be transmitted and transfer levers H32 will be positioned accordingly. The transfer levers associated with the feeler bars 62 which are raised due to perforations in tape 63 are free to rotate clockwise under influence of their individual springs H3 which maintain lugs H2 in engagement with flange IIil. Others of saidtransfer levers are retained in the position shown. in Fig. 1 due to lugs '15 or feeler bars 62 contacting with lugs M4 on the transfer levers to prevent rotation of the transfer levers.

The transfer levers assume positions in accordance with the code for the character .to be transmitted at or just after restoration of bars 156, and due to the engagement of lugs II5 of these transfer leverswith the ends of permutation bars I56, said bars will be forced to assume a position in accordance with the code for the character to be transmitted. I

'Code bars I5!) engaged by transfer levers I02 which are free to rotate clockwise will be forced to the left thereby to align slots I5I under one bar I94 of bell cranks I99. Movement of permutation bars I56 to the left in. Fig. 1 aligns notches I51 in said moved bars with tips I58 of latches lowered latches I 60 engage the notches of operated bars I50 and bell crank I90 selected in accordance with the code of the character to be transmitted will fall into the aligned notches of the code bars I50 and will move the brush 200 thereon into engagement with one of the discs 20 I. Cam I! restores transfer lever I01 and transfer levers I02 after cam I M allows bail I22 to be lowered and after bars I50 are locked in their new positions.

The selected brush 200 approaches its individual disc at or immediately before the radius marked 235A in Fig. 12. The time interval in which all discs 20I rotate their arcs 230 from radius 23IA to radius 235A through the contact point of their brushes 200 provides a transmission interval during which the movement of the receiving tape effects a space between consecutive characters, during which also a brush 200 which has been utilized for the completed character may be lifted and a brush selected to be utilized for the succeeding character may be brought into transmitting position. As the rotation of shaft 56 continues through its facsimileing angle of 300, the selected character will be transmitted by signals similar to signals produced by direct scanning and during that transmission an overlap action will occur in the selecting mechanism of the transmitter 50. Transfer levers I02 will be restored by cam I01, feeler bars 52 will be restored by cam and tape 63 will be advanced by rotation of sprocket wheel 9| and shaft 92 produced by movement of pawl 85 as arm 69 is lowered by cam BI. The transmitting mechanism thus is positioned for its next cycle of selection, which begins immediately as cam SI lowers its follower 51 and the selection is completed in readiness for transfer to a predetermined bell crank I90 during the next interval while the low radius arcs 230 are passing brushes 200.

Receiving mechanism The details of the receiving printing unit are shown in Figs. 6, 7 and 8, and now will be de scribed.

Referring to Fig. 14, power mains H are connected to prime mover 5I2 which may turn shaft 5I3 bearing governor wheel 5M.

Battery 5I5, magnet 5H3, wires 5I1, adjustment screw 5I8 with its contact 5I9 and the contact member 520 on arm 521 of the vibrator 522 form a self-interrupting energizing circuit for the magnet 5I0.

Battery 5I5, vibrator 522, arm 523, contact member 524, contact 525, adjustment screw 520, wire 521, magnet 528 and wire 529 form an energizing circuit for speed governing magnet 528. Pole pieces 530 are attached to magnet 528 and approach governor wheel 514 on opposite sides in such manner that two teeth 53! of the governor wheel may be under two pole pieces at the same time. Switch 532 closes the two circuits just traced.

Pole pieces 530 and magnet 528 are mounted upon plate 533 sleeved upon shaft 5I3 (see Fig. 15). A pointer 534 on plate 533 is associated with a fixed scale 535, and lock screw 536 with knurled head serves to lock plate 533 in adjusted position. This arrangement permits angular adjustment of pole pieces 530 around shaft 5I3 to effect orientation of the receiver.

Adjacent the ends of vibrating arms 52I and 523 are pole pieces 540 and MI of magnet 542 energized by a circuit including battery 543 and adjustable resistance 545.

By the mechanism as above described, the speed of prime mover 5I2 is accurately and locally governed by the magnetic brake mechanism as follows: With switch 532 closed, vibrator 522 will operate, it being necessary at times to manually start the same. After operation of vibrator 522 is initiated it will be continuously maintained by the magnetic drive make and break circuit. Periodic energization of magnet 528 magnetizes poles 530 which will automatically maintain the speed of prime mover 5I2 constant by action of pole pieces 530 on teeth 53I of wheel 5I4. If prime mover 5I2 tends to speed up faster than the rate of vibration of fork 522 the periodic energization of magnet 528 will operate to retard the motor, since teeth 53! on wheel 5M will be pulled into registry with pole pieces 530 each time magnet 52B is energized. The same result occurs if the motor 5| 2 slows up in its operation behind vibrator 522, and in this way the speed of the receiving mechanism is very closely regulated by the vibrator or tuning fork 522.

If the speed of the receiver is not exactly in synchronism with that of the transmitting mechanism, as will be apparent from an inspection of the printed tape at the receiver, adjustment of rheostat contact 545 will vary the magnetic effect of poles 540 and MI on tines 52I and 523 to accelerate or retard vibration of the vibrator 522 to secure accurate synchronization.

Shaft 5|3 carries driving gear 550 which meshes with gear 55I on shaft 552. Shaft 552 carries and drives pinion gear 553 and printing or recording wheel 554. Pinion 553 meshes with and drives gear 555 on the shaft 556 which shaft bears and drives feed roller 551. 1

Referring to Figs. 6 and '1, feed roller 551 has a companion presser roller 558 (Fig. 14) suitably urged towards roller 551. Driven between the two rollers are two tapes 500 and 56L Tape 560 constitutes the record receiving surface and tape 55I is a pigment carrying tape such as carbon transfer paper or an ink ribbon of the type used in typewriters.

Printing wheel 554 is provided on its cylindrical surface with symmetrical spiral knife edges 555, (Fig. 6), which are normally substantially in contact with the tapes.

Under the tapes and opposite printing wheel 554 is the operating member or platen 566 having knife edge 551 arranged transversely at a slight angle with respect to the tapes as will more fully hereinafter appear. Member 565 is attached to an armature member 568 of cup form supported upon a spring mounting 569 which carries the recorder operating winding 410. Receiver field magnet 515 has winding 511 and core 515 having extension poles 518 which terminate closely adjacent to and the ends of which partially encompass and fit closely around winding 410. Field winding 511 is connected to battery 580 and is normally energized.

In Fig. 8, tapes 560 and 56I are shown as viewed from above in Fig. 6, and diagonal lines 585 show a development of edges 565 of printing wheel 554. Dotted line 551 is the edge 561 of the recording platen of Figs. 6 and 7, shown dotted because it is below the tapes 560 and 56L This line, it will be noted is at a slight angle from the normal or transverse line of the tape. At 586 are shown the printed lines which compose the ultimate record; as will appear in the description of the operation.

Receiver operation In operation of the receiver so far described, wheel 554 is driven constantly at a proper recording speed as will more fully hereinafter appear, and received current impulses impressed upon the operating winding ilo are in such a direction as to move cup-shaped armature ttfl carrying armature member 5% upwardly, by cooperation with the force of the field of magnet 575, marking signal current repels against field force ofmagnet 5715 and winding tie is propelled upward. In absence of marking signal current, mountingspring 569 drawsedge 561 downward and relieves pressure from tape 5%. In double current working a reverse-polarity spacing signal current cooperates with field force of magnet 575 to assist spring 569, or to obviate this spring.

From Fig. 7 it will be noted that upward movement of armature member 5% causes engagement of knife edge 56'! against the under surface of tape 560 pressing it with transfer paper tiiil'between edge 587 and spiral edges 565 on rotating receiver wheel 554. 7

From developed Fig. 8 it will be seen that the spirals 565, represented in this figure by lines 585, are so arranged that two of the spirals intersect a line drawn perpendicular to the edge of the tape. Lines 585 which represent spiral edges 565 will have a motion over the tape 560 in the direction of the arrow 581, due to rotation of wheel 554, while tape 560 has a slower motion in the direction of arrow 59!] due to turning of roller Should armature 566 be operated vertically by an incoming signal impulse when knife edge 55? is in the relative position shown in dotted lines in Fig. 8, two dots will be printed upon the tape 5% at the two points where said knife edge 5W intersects spiral edges 585, or at points fitIA, 5MB. Should this vertical movement of knife edge 551 be repeated a brief interval later, a pair of dots will again be printed, but above the first pair of dots 561A and 5613 because of the intervening movement of the tape and of spiral edges 585. If a letter is to be transmitted having a long vertical portion, such as the letter R, the knife edge 561 will be held in raised position by a comparatively long signal when the line is to be recorded so that each spiral line 585 will move to the right of Fig. 8 a distance such that-any intersecting point will in effect, move vertically half the width of the tape. If an incoming signail is received when the edge 56'! occupies the position shown dotted in Fig. 8, a vertical line will be marked on the tape 560 from EMA. nearly to 551B, due to the movement to the right of spiral edge 585 contacting continuously with 561. A vertical line will also be drawn from 5MB to the top of the wheel 554 and from the bottom of wheel 554 almost up to 567A, as seen in the letter R at the left side of the tape. Owing to the comparatively slow but continuous motion of the tape 56!! the lines printed thereupon do not colines 586 of Fig. 8.

The vertical line so recorded on the tape will correspond to black unit areas extending from I point 231 to point 238 of Fig. 13, and will be trans- .segment 255.

'mitted by engagement of one of the brushes 2% with portion 237A of the R disc (Fig. 12. Further movement of'the R disc at the transmitter will result in non-contacting relation of the brush corresponding to low portion 243, then contact with high portion 239A, then non-contact with low portion 2&3, then contact with high portion ZMA, then non-contact with low segment 2% in Fig. 2.2 and the successive contacting for the two high portions 2H spaced by the non-contacting These long lines recorded from high portions 2371A, 239A and ZMA unite upon record tape 5% to form the stem portion of letter R being recorded. The two smaller contacting portions 2H will result in four dashes or lines adjacent the vertical lines on the tape 5% which will thus begin the horizontal portions of the letter R as seen in Fig. 13, it being understood that the equivalent of two Rs is being printed. Continued rotation of the R disc will transmit signalling impulses spaced by proper blank signals to develop the letter R in one complete and two fractional characters on the tape 5%. In the same manner each character to be transmitted is developed by successive impulses received from the selective code discs upon the coil Mil of the receiving instrument.

Should knife edge 56 be held upwardly for a long period of time, for example, while one of the sp'iral'lines 5% passes completely over the knife edge 5W, successive vertical lines would be printed upon the tape 560 by the passage of successive edges 585 of the printing wheel and would produce substantially a solid printing upon the tape.

Since a continuous transmitted current or marking condition would produce a succession of these vertical black lines which would thus blacken the entire surface of the record tape, and since the omission of a current or transmission marking will leave a blank space or light areas, legible records may be produced by omitting the proper combinations of marking signals. The combinations of marking and spacing conditions necessary for each character to be transmitted 1 are controlled by a code disc 20! individual thereto, the proper code disc being selected by selection of its brush 209 under control of the transmitting tape.

Spacing between letters, as previously explained, is produced by the initial omission of current or transmission of a spacing signal preceding each character transmitted.

As previously stated, due to the overlap of the spiral knife edges 565, a double record will be produced on tape 5% as shown in tape 59I of Fig. 9. It will be clearly understood that a receiver to reproduce three or more lines of characters may be attained by providing spiral knife edges 565 so that a larger number of these edges overlap at all points and a proper adjustment of speed of wheel 55%.

Duplicate records may also be secured by providing a plurality of'tapes 566 each having a transfer or carbon paper 56! superimposed one upon the other in a manner well known in'the typewriting or telegraph art.

Synchronization The improved duplicate record recorder permits wide variations in receiver and transmitter speeds without loss of signals and permits the use of novel methods of speed control for practical operation without the necessity for special control or synchronizing signals or devices. This is due H to the fact that at least one complete character is always received and the position of the characters on the receiving record indicates the synchronous or asynchronous condition of the apparatus and an operator can, without interruption of signalling, visually note deviations of the receiver from synchronism, and can adjust the receiver speeds without loss of signals.

If the speed and phase of rotation of printing wheel 554 correspond exactly to the speed of rotation and phase of the transmitting code discs,

the record will be received as shown upon tape 59! of Fig. 9, as one complete set of characters uniformly spaced from the edges of the receiving tape and two fractional rows. Should the speed of wheel 554 be faster than that of code discs of the transmitting instrument, the record will be received as shown on the tape 592 of Fig. 10. If the speed of the receiver is slower than the transmitter the resultant record will be as shown upon the tape 593 (Fig, 11). A continuance of the effect shown in Fig. 11 would carry the median row of characters to the lower edge of the record tape where the reader would then cease to read one line of characters and would begin to read the next vertical line thereof.

The most important feature of the two letter method of recording is the elimination of all control between the sender and receiver. This is very desirable in radio transmission since foreign impulses such as static cannot interfere with the proper and legible placing of the letter on the record tape. Should the effect repeat itself persistently, the speed of the vibrator at the receiving station may be manually adjusted to restore the receiver as closely as desired to synchronous speed by movement of the rheostat 545, as described in connection with Fig. 14, during reception and without loss of signals.

Referring to the photographic recorder or receiver of Fig. 16, adjustable governor shaft 552 of Fig. 14 appears in Fig. 16 and bears scanning disc 9!!! and gear 9| l, in mesh with gear M2 on shaft 9l3. Gear 9l4 on shaft 9I3 meshes with gear 9I5 on shaft 9H5, which bears roller 9H which in turn cooperates with a companion roller 9l8. Tape 9l9 passes between rollers 9H and 9l8 and then passes through tank 929. At 92l are shown undeveloped photo efiects and at 922 are shown developed characters upon the tape 9l9.

In disc 9H) are a number of holes 939 arranged in a circular arc. A system of optical condensers 93I is positioned upon an axis 932 preferably parallel to the axis of shaft 552, and intersecting the path of holes 930, and also intersecting tape 9l9.

Neon lamp 933 is positioned on axis 932 and optical condensers 93| are arranged to throw a beam of light 932A on disc 9H! whose diameter is at least equal to and preferably is slightly greater than the spacing between three holes 939. There are thus at least two holes within the area 932A of the light beam at all times and a signal pulse cannot be lost. If this provision was not made, exact synchronism of the transmitter and recorder would be necessary or else some light impulses would be received when there was no hole in the area of the light beam and there would be no corresponding record made.

By the arrangement described, a further advantage is obtained in that duplicate records are printed as shown on tape 922 so that if transmitter and receiver are not in exact synchronism, at least one complete and legible message Will be printed.

If the receiver is running out of synchronism, as disclosed by an examination of the tape, the orientation adjustment shown in Fig. 15 can be manually adjusted to obtain the printing of the record with one full row of characters in the center of the tape and synchronous speed may be easily maintained by this adjustment.

The neon lamp 933 is connected in series with battery 996, resistance 93! and wire 938. Battery 996 is connected through battery 939 to filament 999, heated by battery 94! and forming a part of thermionic valve 942. Wire 938 is connected by wire 943 to plate 944 of valve 942. Grid 945 of valve 942 is connected through battery 946 to induction coil 433 and filament 949, which is also connected by wire 94! to induction coil 433.

The spacing of holes 939 in disc 9H] is slightly greater than the height of the symbols or letters on tape 9|9. This has the effect of giving a blank space between vertical rows of letters on receiver tape 919, similar to the record shown in Fi 9.

Operation of the receiving apparatus, Fig. 16, begins with the action of repeating coil 433, which in accordance with the received signals impresses an alternating current upon grid 945 and filament 949 of valve 942, through wire 94'! and battery 946.

The source from which the signals are sent and the communication channels over which the signals are propagated to reach the induction coil 433, is not of the essence of the description in the study of this figure, since the signals may originate in a device modeled upon the disclosure of Fig. 1, or any other suitable transmitting mechanism.

The signals impressed upon grid 945 are alternating in nature and of voice frequency. These signals are repeated in amplified intensity over the discharge circuit comprising battery 939, filament 949, plate 944, wire 943, wire 938, neon lamp 933 and battery 939. There is also the derived circuit or shunt 931, which reduces the current through lamp 933 and which preserves the continuity of the current through plate 944 during periods of inactivity of lamp 933. The circuit in cluding battery 93B, resistance 931, wire 938 and lamp 933 provides for lamp 933 a potential nearly sufficient, yet insufficient, to operate lamp 933. When the plate current of valve 942 increases, the potential upon lamp 933 is raised to operating value and lamp 933 glows. On the other hand when due to the control of the grid 945, plate current from valve 942 decreases, potential upon lamp 993 is decreased and the lamp darkens. Each positive pulse of voice frequency upon grid 945 thus propagates a signal to flash lamp 933, which responds with rapid flashes of voice frequency when current is received from induction coil 433, and which remains dark when no such current is received. By the flashing of lamp 933, light is supplied to the system of optical condensers 93E, and a beam of light 932A is impinged upon disc 9l0 and passes through two holes to impinge in two places upon the photo-sensitive recording tape 92L By motion of the tape and the regulated speed of disc 9H), letters will be formed in latent photographic images 92l, upon the moving tape 9|9, which then passes through the developing tank 920 of any suitable type, and emerges with a visible record, as shown in characters 922. The nature of the record is similar to that discussed in connection with Figs. 9, 10, and 11, and is subject to the same corrective measures. The shaft 552is subject to the correcwith Figs.

embodiment is therefore to be considered in all respects as illustrative and not restrictive,.the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which comejwithin the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is: r

l. A method of operating a facsimile telegraph system, which comprises simultaneously recording a plurality of images in adjacent relationship on a single strip of recording medium of each transmitted character whereby legible records are received with wide variations in the speeds of operation of transmittingand receiving mechanism.

.2. In a facsimile telegraph system, a printing receiver, a tape, and means to print thereon in adjacent relationship at least two duplicate received characters of each transmitted character whereby the received message is fully legible when the receiver is not in synchronism with its transmitter.

3. In a facsimile telegraph, a. receiver having signal responsive means for flashing a light ray, a light sensitive element, and means to impinge said light ray on said sensitive element at a plurality of points to facsimile in duplicate a received symbol.

4. In a facsimile telegraph receiver, a light sensitive element, means responsive to received signals for impinging a light ray thereon, a perforated disc positioned in the path of said light ray, the perforations in said disc being so spaced that said ray always passes through two perforations to said light-sensitive e1ement,'whereby duplicate symbols are reproduced thereon.

5. In a facsimile telegraph system, transmitting apparatus, receiving apparatus, means to simultaneously produce upon'one record a plurality of images of each transmitted character whereby legible records are received substantially independent of speed control between the transmitting and receiving apparatus.

6. In apparatus for transmitting and recording images, the combination of a transmitter comprising a rotating image record, means for scanning each element of the image record to produce corresponding electrical impulses, a recording device comprising a support for an image record receiving element, and means cooperating with said record receiving element and responsive to the transmitted electrical impulses for recording each transmitted element of the image twice in adjacent relation and spaced to produce duplicate images, whereby one of the two recorded images will be uninterrupted.

7. In apparatus for transmitting and recording images, thecombination of a transmitter comprising an image record, means for scanning each element of the image record to produce corresponding'electrical impulses, a recording device comprising a support for an image record receiving element, and means cooperating with said record receiving element and responsive to the transmitted electrical impulses for recording each transmitted element of the image simultaneously in duplicate in adjacent relation and spaced to produce duplicate images, whereby one of the two recorded images will be uninterrupted.

8. Ina facsimile telegraph, a receiver having means to produce a light ray to record characters, a light sensitive recording element, and means to impingesaid light ray on said recording element atga plurality of points farther apart than the vertical dimension of a recorded character to facsimile in duplioatea received character with separation between the duplicate records.

, 9. In a facsimile telegraph receiver, a light sensitive element, means responsive to received signals for impinging a light ray thereon, and a perforated disc positioned in the path of said light ray, thesuccessive perforations in said disc being spaced, closer together than the width of a receiving tape, thereby presenting two light rays through two perforations simultaneously to said light sensitive. element. i

10. In a facsimile telegraph receiver, aligh sensitive element, means responsive to received signals representing characters for impinging light rays thereon, and a-perforated disc positioned in the path of light whose perforations per- 'mit rays of light through said disc toimpinge transmitting and receiving apparatus.

12. In a facsimile recorder for recording simultaneously a plurality of parallel lines on a recording tape, means for moving the tape continuously, a rotating printing wheel, and a recording edge cooperating with said wheel for printing set at an angle to said parallel lines, said angle being such that the difference between the rotation of the wheel and the movement of recording tape is compensated.

13. In a facsimile recorder, a cylindrical recording member having spiral edges, and a recording member having a straight edge, the angle of said spiral edges being such that two or more spiral edges engage said straight edge at one time.

14. In a facsimile recorder, means to record multiple images upon a recording surface to appear as a complete image accompanied by fractional images above and below the complete image, and manual control means for shifting the position of the currently received image with reference to the edges of the surface and without stopping the operation of the recording means.

15. A method of operating a facsimile telegraph system which comprises, simultaneously recording in a plurality of places upon a single record surface to produce a single complete image and a plurality of fractional images of each transmitted character, whereby legible records are produced despite wide differences between speeds of transmitting and receiving mechanisms.

16. In a telegraph system, a printing receiver, a tape, and means to print simultaneously in a plurality of spaces on said tape to produce one complete record and a plurality of mutilated records of a character corresponding to a received code signal when the receiver is out of phase with said received code signal.

1'7. In a facsimile telegraph system, transmitting apparatus, receiving apparatus, means to produce simultaneously upon one record a plurality of images comprising one perfect image and two fractional images of each transmitted character whereby legible records are received substantially independent of speed control between the transmitting and receiving apparatus.

18. In apparatus for transmitting and recording images, the combination of a transmitter comprising a rotating image record, means for scanning each element of the image'record to produce corresponding electrical impulses, a recording device comprising a support for an image record receiving element, and means cooperating with said record receiving element and responsive to the transmitted electrical impulses for recording each transmitted element of the image twice in adjacent relation and spaced to produce a plurality of images when said receiver is out of phase with said transmitter, said record receiving element having an image recording receiving area greater than the area of any recorded received image, whereby one of the recorded images will be uninterrupted.

19. In apparatus for transmitting and recording images, the combination of a transmitter comprising an image record, means for scanning each element of the image record to produce corresponding electrical impulses, a recording device comprising a support for an image record receiving element, and means cooperating with said record receiving element and responsive to the transmitted electrical impulses for recording each transmitted element of the image simultaneously in duplicate in adjacent relation and spaced to produce a perfect image in a mean position accompanied by mutilated duplicate images, whereby one of the recorded images will be legible.

20. In a facsimile telegraph, a receiver having means to produce a plurality of light rays to record characters, a light sensitive recording element, and means to impinge said light rays on said recording element at a plurality of points farther apart than the vertical dimension of a recorded character to facsimile a received character accompanied by fragmentary duplications thereof with separation between the recorded facsimile character and the fractional duplicate records.

21. In a facsimile telegraph system, transmitting apparatus, receiving apparatus, and means to record simultaneously a plurality of images of each transmitted character separated and in different axial zones upon a tape whereby legible records are received substantially independent of phase control between transmitting and receiving apparatus.

EDWARD E. KLEINSCHMIDT. EDWARD F. KLEINSCHMIDT. 

